The Rights of a Believer on a Fellow Believer.
Kitāb al-Muʾmin|Volume 1|Book 1|Chapter 4
96 - وعن أبي عبد الله (ع) قال المؤمنُ أخو المؤمن يحِقُّ عليه نصيحتُه ومواساتُه ومَنعُ عدوِّه منه.
96. It has been reported that Abu 'Abd Allah عليه السلام said: A believer is a brother to another believer and it is his right that he should counsel him, sympathize with him and prevent his enemies from harming him.